Researchers at The University of Texas M. D. Anderson Cancer Center are testing the non-invasive tumor ablation method that may one day replace surgery to remove some cancers.

Led by Marc Fenstermacher, M. D., a diagnostic radiologist, and John Hazle, Pd.D., a physicist, both in M. D. Anderson's Department of Diagnostic Radiology, the Phase II clinical trial is open to 15 breast cancer surgical patients with tumors no larger than 2 centimeters. The study is sponsored by the treatment's developer, TxSonics of Dallas.

M. D. Anderson was the first U.S. site to use the procedure for the care of cancer patients.

The therapy, known as Magnetic Resonance Guided Focused Ultrasound Therapy, combines the imaging technology of MRI machinery with ultrasound waves to kill cancer cells with heat rather than removing the cancer via traditional surgery.

In the non-invasive technique, the MRI is utilized to precisely locate the cancerous breast tumor and to determine the location of focal spots within the tumor. A series of short pulses of ultrasound waves are then delivered to each focal spot in 10-second intervals, killing the tumor's cancerous cells with heat from the waves. Throughout the delivery of the ultrasound waves, the MRI is simultaneously measuring the temperature change in the cancerous area.

"The ultrasound waves treat the tumor by raising the temperature of the cancerous tissue to more than 60 degrees Celsius", said Dr. Hazle. "At that point, the tumor tissue dies because the cells are coagulated and there is no blood flow to the tumor. The tumor is literally cooked."

The outpatient procedure is performed while the patient is lightly sedated, with the the patient and doctor in communication throughout the treatment.

"A tremendous value of this therapy is that the procedure can be repeated over and over in a single treatment episode," said Dr. Fenstermacher.

"Immediately after the procedure, magnetic resonance images are taken to ensure that we have killed the tumor," he said. "If there are still signs of cancer, we can go back and treat the malignant area with the same therapy right then and there."

To further ensure that the entire cancerous breast tumor has been completely ablated, trial participants will undergo traditional surgery about two weeks following the Magnetic Resonance Guided Focused Ultrasound Therapy. Patients also may undergo additional complementary treatments - such as radiation or chemotherapy - as determined by each patient's physician.

"For this critical trial, surgery is necessary to obtain a pathology report and confirm that there are no residual, living microscopic portions of the cancerous tumor left." said Dr. Hazle.

According to Dr. Fenstermacher, initial results from the first two patients suggest that this innovative therapy is highly effective in killing malignant tumor cells. "In the first patient, there were signs of residual tumor in the excised lumpectomy specimen, but we believe this was in an area that we did not treat with the Magnetic Resonance Guided Focused Ultrasound Therapy. In the second patient, the demarcation between the treated and untreated area was clearly seen and exactly matched the post-therapy imaging. No viable tumor was found in the treated area," said Dr. Fenstermacher.

The treatment's side effects appear minimal - with patients feeling only quick waves of heat to their breast throughout the treatment. Participants may also feel mild discomfort in the treated area for 24 to 36 hours post-treatment.

According to Dr. Hazle, the concept of administering thermal therapy waves goes back to the development of the ultrasound. However, before now, there was little guidance to ensure that the ultrasound wave hit the cancerous focal target.

"It was not until we were able to combine the high intensity focused ultrasound therapy with the MRI imaging technology that we were able to give the sonification and know within seconds if, first, we heated up any tissue at all, and second, if we heated up the cancerous tissue we were trying to ablate," said Dr. Hazle.

Dr. Fenstermacher adds that the impact of the Magnetic Resonance Guided Focused Ultrasound Therapy could be far reaching, potemtially serving more than 500 breast cancer patients a year at M. D. Anderson alone.

"In the not too distant future, we think that this non-invasive, patient-friendly therapy may replace surgery as a primary method of treatment for those with breast cancer. It also looks like a very promising therapy for other types of cancers, with studies planned to investigate its effectiveness in treating tumors of the uterus and soft tissue sarcomas."

Patients eligible for the clinical study must be M. D. Anderson surgical patients who meet the following criteria: have breast tumors no larger than 2 centimeters, have not been treated with chemotherapy in the last 3 months and be physically able to undergo an MRI. For more information, individuals may call or call askMDAnderson at 1-877-632-6789.